Dashpot for time switches



c. E. SUNDBERG DAsHPoT FOR TIME SWITCHES Filed July 24, 1929 May 2,A1933.

fnf/72102 Patented May- 24, 1933 i UNITED STATES PATENT OFFICE CARL E.SUNDBERG, or QUIFNCY, MASSACHUSETTS, ASSIGNoB. T ALBERT a Jj n. ANDERSONMANUFACTURJNG COMPANY, oF SOUTH BosToN,wMAssAcHUsETTs, A

CORPORATION OF MASSACHUSETTS DASHPOT FOR TIME SWITCHES Application ledJuly 24, 1929. Serial 310,380,524.

This invention relates to apparatus f or controlling the fiow of gas,water, electricity or the like, wherein a movable member 1s capable ofbeing moved into one position substantially in an instant and of beingmoved into another position after the lapse of a predetermined time.

The invention in the present instance is embodied in an apparatus forcontrollingan electric circuit, and has for its object to provide asimple, inexpensive and reliable apparatus in which provision is made.for Closing the circuit controller by manually-movingy a piston in onedirection in its cylinder, and for opening the circuit controller aftera lapse of time by moving the piston in the opposite direction at adifferent speed.

Provision is also made for varying the i length of time the circuitcontroller remains closed to meet diii'erent conditions of use.-

These and other features of this invention will be pointed out in theclaims at the end of this specification.

Fig. 1 is a plan view of one form of apparatus embodying this invention;

Fig. 2, a vertical section of the apparatus shown in Fig. 1; f

A Figs. 3, .4' and 5, enlarged details of parts of the apparatus shownin Figs. 1 and 2,

"Fig. 4 being a section on the line 4-4,

Fig. 3

Referring to the drawing, re resents a cylinder containing a piston 12tted airtight therein and provided with a hollow piston rod 13 which isextended through a head 14 of the cylinder and through a face .plate 15of a casing 1,6 in which the cylinder 12 is located. C

The hollowpiston rod 13 is provided with a relativel-ylarge bore 18 andwith a smaller bore 19 whose inner end wall 20 forms a seat for a valve21 by which communication between the said bores maybe "cut oi.

Y be described.

The stem 23`of the valve 21 prqjects beyond the end of the piston rodand is slabbed oi at one side as shown in Fig. 4, to form between it and.the inner wall ot the smaller bore 19 of the hollow piston rod apassage 25 which Connects the hollow piston rod 13 below the valve seat20 with the atmosphere when the valve 21 is 'removedfrom its seat, whichis e'ected by the operator pressing upon a button or head 27 on thevalve stem 23.

The valve stem 23 is hollow and extends into a chamber 281in the head27, which chamber is in open communication with the atmosphere, andconstitutes a valve chamber in which is located a valve vfor cuttingoilz' communication between the portion oif the cylinder l0 below thepiston and the atmosphere.

In the present instance, this valve is shown f as @washer 30 of leatherorother suitable material which is mounted on a screw 31 beis providedwith a notch 36 see Fig. 5),

which Constitutesan air-port for the passage of air out of the chamber34 when the piston is forced downward in its cylinder by-the operatorpressing on the head 27, which is engaged with the upper end of thehollow piston rod 13 to move the latter, but does when the air outletvalve 21 is opened by 34 can pass out of the cylinder as the piston ismoved toward the bottom of the cylinder. i

The piston 12 may be automatically moved in the opposite direction by aspring 40 located in the cylinder and extended into the I cylinder, fora purpose as will be described. The upper end of the hollow iston rod 13not close the airport or netch36, so that,`

.movement ofA the head 2,7V into Contact with the hollow piston rod 13',air in the chamber 40 air inlet 'port 50 in the body portion of the"hollow piston rod 13 to engage the valve 21 and normally seat the same.

The lower end of the spring 40 may encircle a uiding rod 41 attached toa disk 42 located in the cylinder.

From the above description, it will be seen that the chamber 34 belowthe piston is provided with an air inlet formed by the hollow valve stem23 and with an air outlet formed by the hollow piston rod 13 and thepassages 25, 36.

It will also be seen that the air inlet is ycontrolled by a valvecomprising the split screw 3l and the washer 30,'and that the volume ofair admitted into the chamber 34 of the cylinder 10 may be controlled orregulated by exposing tothe atmosphere more or less of the passage 35 inthe screw 3l.

It willalso be seen that the air outlet for the chamber 34 is providedwith avalve 21 which tits the bore 18 of the hollow piston rod 13loosely, so that when the valve 21 is forced off its seat by theoperator, air in the chamber 34 and in the hollow piston rod may passthrough the passage 25 and notch 36 to the atmosphere,l with the resultthat when the piston 12 has been moved to near the bottom of itscylinder, very little air will remain inthe chamber 34 and bore 18.

On the return movement of the .piston 12 'by the spring 40, the pistoncreates a partial vacuum in the chamber 34, which resists the action ofthe spring 40 and delays the return for aprcdetermined lapsed time,which is regulated by adjusting the air inlet valve 31 so as to requirea given time to elapse before sufficient air isadmitted into the chamber34 to reduce the vacuum sufficiently to permit the spring 40to returnthe piston to near its starting'position and uncover an cylinder so asto admit a larger. volume of air and effect a balance of the piston,which enables the-'spring 4() to complete its return movement at aquicker rate toward the end of said return movement. ,y

The piston 12 movableinto one position at one speed and movable intoanother position at a reduced speed, is utilized to operate a circuitcontroller or switch 52, a known construction of which is herein shown,and is provided with a movable contact member 53 which co-operates witha stationary contact member 54 in a manner well understood.

The movable contact member 53 is represented as a lever pivoted at 55(see Fig. 2) and has connected to it oneend of a movable member or lever56. pivoted at 57 and having an arm 58 extended into the cylinder 10above the piston 12 through a slot 59 in said cylinder.

4The arm 58 is normally extended into the path of movement of a devicewhich is movable with the piston.

In the present instance, this device is 'an additional air inlet portshown as a bracket whith is suitably attached to the hollow piston rod13 to move therewith and is provided with a vertical section 60, a.horizontal section 61 and an inclined section 62.

The bracket and the arm 58 are arranged so that the latter is below theinclined section 62 when the switch or circuit controller is open asrepresented in Fig. 2. lVhen the operator moves the piston downward inits cylinder in the direction indicated by the arrow 64, the inclinedsection G2 is engaged with the arm 58 and cants or turns the arm into asubstantially vertical position out of the path of the bracket andallows the piston to be moved to the end of its stroke in the directionindicated4 by the arrow 64.

Movement of the arm 58 effects closure movement of the movable contactmember 53 which vis held in its closed position by the arm 58 engagingthe vertical section 60 of the`bracket. 4

The switch remains closed for a predetermined tim'e. or until the pistonhas been returned to its normal or startin position by the spring 40, atwhich time t e` bracket is moved above the arm 58 and the latter ismoved by a spring 66 into its starting position, represented in Fig. 2,and the movable contact member 53 is also moved into its open position.A

Apparatus of the character described, is especially useful forcontrolling machines or apparatus operated by electric motors whosecircuit is controlled by the-switch, and as it may be desirable tooperate the machine for different lengths of time according to thecharacter of the work being performed by the machine or apparatus,provision is made for enabling the machine to be operated for differentintervals of time.

In the .present instance, this result is accomplished by providing the clinder' with 70 which is located between the port 50 and the bottom ofthe cylinder, so that a shorter interval of time isrequired for thepiston to uncover the port 70 than is required to uncover the port 50.

To illustrate: Suppose that a washing machine is being controlled. Alsosuppose that for one kind or quantity of material it is desired that thewashing machine should be run for ten minutes, and that for a finer ormore delicate material, it is desired the .machine should be stopped atthe end of YYw14. In an In the present instance, the face late is shownas rovided with the letters I.. and L. I.-in icative of the shortinterval and the long interval, and said letters may be arrangedso thatwhen the pointer registers with the letters L. I. as shown in Fig. l,the port 70 will be closed by the valve 72, and when the pointerregisters with the letters S. I. the port 70 will be. opened by thevalve 72.

From the above description, it will loel seen that the apparatus issimple, inex- Y pensive, and yet reliable in operation.

One embodiment of the invention is -herel5 vention to the particularyconstruction shown.

What isclaimed is:

valve to seat the same, said valve having a hollow stem forming an airinlet into said hollow piston rod and said cylinder and co-operatingwith the hollow piston rod to form an air outlet passage for saidcylinder, and means carried by said hollow valve stem for controllingthe admission of air into said cylinder through said hollow valve stem.

In testimony whereof, I have signedrmy name to this specilication.

CARL E. SUNDBERG.

in shown, but itis not desired to limit the in- A 1. In anapparatus ofthe character described, in combination, a c linder, a piston `locatedtherein and provi ed with a hollow piston rod, a valve located in saidhollow piston rod for controlling the passage of fluid out of thecylinder through said hollow piston rod, a evice actuated by move-g mentof the piston into one osition in one period of time, and means orcontrolling the admission of fluid into said cylinder to permit a longerriod of time to elapse before the piston omes effective to permit thesaid ldevice to be moved into another .position by' movement of saidpiston` into .another position.

2. In combm tlon, a c linder, a piston located therein and provi ed witha hollow 435 piston rod, a valvev located'in said hollow piston rod .andmovable therein for controlling the passage of-luid out of the cylinderthrough said hollow piston rod, and an adjustable valve carried by saidhollow iston 4 rod for controlling admission of ui into the saidcylinder.

3. In an apparatus Vof the character described, in combination, acylinder, a piston located therein and. provided with a hollow valveco-o rating with said seat, a sp within saidliollow piston rod ac on -smvalve to seat the same, said valve a hollow stem forming an air-inletinto said 5 hollow piston rod and said cylinder and cooperatingwith the vhollow piston rod to form anair outlet p for said cylinder ascrew -in threaded engagement with hollow valve .stem and rovided with apassage for airV into said ho ow valve stem, and

45 piston rod having therein a valve seat, a

a devicel carried by said hollow valve stem 'and (so-operating withthehollow piston rod to e'eet movement of the piston in one direction -insaid cylinder.

apparatus `of the character described, -in com nation, a cylinder, apiston located therein and provided with a `hollow piston rod havingtherein a valve seat, a valve eo-o rating with said seat, a sp1-msA 55.within sai 'hollow piston rod acting on sai

